>>13399812>>13399831>>13399836Seriously, the Kampfer is missing out on a skirt (Which are usually just slabs of metal draped from the waist to protect the upper legs), and has partially exposed shoulders. Everything I've read over the years has said that it has 'less' armor. Nothing has actually said that the armor it does have is less effective.
And once again, our only available evidence is in a predetermined fight against a Gundam, in an era where ballistics will fuck up ANY MS that isn't a Gundam. Put any Zeonic MS from that time in the same position and it wouldn't fare any better (barring MAYBE the Gogg, since their very first approach to deep-sea MS was very heavy armor to help withstand pressure)